///////////////////////////////////////////////////////////////////////////////////
/// OpenGL Mathematics (glm.g-truc.net)
///
/// Copyright (c) 2005 - 2015 G-Truc Creation (www.g-truc.net)
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// Restrictions:
///		By making use of the Software for military purposes, you choose to make
///		a Bunny unhappy.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.
///
/// @ref core
/// @file glm/detail/func_exponential.inl
/// @date 2008-08-03 / 2011-06-15
/// @author Christophe Riccio
///////////////////////////////////////////////////////////////////////////////////

#include "func_vector_relational.hpp"
#include "_vectorize.hpp"
#include <limits>
#include <cmath>
#include <cassert>

namespace glm {
    namespace detail {
#	if GLM_HAS_CXX11_STL
        using std::log2;
#	else

        template<typename genType>
        genType log2(genType Value) {
            return std::log(Value) * static_cast<genType>(1.4426950408889634073599246810019);
        }

#	endif

        template<typename T, precision P, template<class, precision> class vecType, bool isFloat = true>
        struct compute_log2 {
            GLM_FUNC_QUALIFIER static vecType<T, P> call(vecType<T, P> const &vec) {
                return detail::functor1<T, T, P, vecType>::call(log2, vec);
            }
        };

        template<template<class, precision> class vecType, typename T, precision P>
        struct compute_inversesqrt {
            GLM_FUNC_QUALIFIER static vecType<T, P> call(vecType<T, P> const &x) {
                return static_cast<T>(1) / sqrt(x);
            }
        };

        template<template<class, precision> class vecType>
        struct compute_inversesqrt<vecType, float, lowp> {
            GLM_FUNC_QUALIFIER static vecType<float, lowp> call(vecType<float, lowp> const &x) {
                vecType<float, lowp> tmp(x);
                vecType<float, lowp> xhalf(tmp * 0.5f);
                vecType<uint, lowp> *p = reinterpret_cast<vecType<uint, lowp> *>(const_cast<vecType<float, lowp> *>(&x));
                vecType<uint, lowp> i =
                        vecType<uint, lowp>(0x5f375a86) - (*p >> vecType<uint, lowp>(1));
                vecType<float, lowp> *ptmp = reinterpret_cast<vecType<float, lowp> *>(&i);
                tmp = *ptmp;
                tmp = tmp * (1.5f - xhalf * tmp * tmp);
                return tmp;
            }
        };
    }//namespace detail

    // pow
    using std::pow;

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<T, P> pow(vecType<T, P> const &base, vecType<T, P> const &exponent) {
        return detail::functor2<T, P, vecType>::call(pow, base, exponent);
    }

    // exp
    using std::exp;

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<T, P> exp(vecType<T, P> const &x) {
        return detail::functor1<T, T, P, vecType>::call(exp, x);
    }

    // log
    using std::log;

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<T, P> log(vecType<T, P> const &x) {
        return detail::functor1<T, T, P, vecType>::call(log, x);
    }

    //exp2, ln2 = 0.69314718055994530941723212145818f
    template<typename genType>
    GLM_FUNC_QUALIFIER genType exp2(genType x) {
        GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559,
                          "'exp2' only accept floating-point inputs");

        return std::exp(static_cast<genType>(0.69314718055994530941723212145818) * x);
    }

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<T, P> exp2(vecType<T, P> const &x) {
        return detail::functor1<T, T, P, vecType>::call(exp2, x);
    }

    // log2, ln2 = 0.69314718055994530941723212145818f
    template<typename genType>
    GLM_FUNC_QUALIFIER genType log2(genType x) {
        return log2(tvec1<genType>(x)).x;
    }

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<T, P> log2(vecType<T, P> const &x) {
        return detail::compute_log2<T, P, vecType, std::numeric_limits<T>::is_iec559>::call(x);
    }

    // sqrt
    using std::sqrt;

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<T, P> sqrt(vecType<T, P> const &x) {
        GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559,
                          "'sqrt' only accept floating-point inputs");
        return detail::functor1<T, T, P, vecType>::call(sqrt, x);
    }

    // inversesqrt
    template<typename genType>
    GLM_FUNC_QUALIFIER genType inversesqrt(genType x) {
        return static_cast<genType>(1) / sqrt(x);
    }

    template<typename T, precision P, template<typename, precision> class vecType>
    GLM_FUNC_QUALIFIER vecType<T, P> inversesqrt(vecType<T, P> const &x) {
        GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559,
                          "'inversesqrt' only accept floating-point inputs");
        return detail::compute_inversesqrt<vecType, T, P>::call(x);
    }
}//namespace glm
